When Joel Edgerton sidles into view at a downtown Toronto restaurant, he cuts an immediately conspicuous figure, despite being less physically imposing than the first time we met each other, around the time of his breakout American film Warrior.

“Maybe I have lost a little weight,” he drawls, in a thick Australian accent that sounds as if it hasn’t changed one iota from his days growing up in the Western Sydney suburb of Blacktown. “I wasn’t trying to lose it. Should I be worried?”

Slimming questions aside, what’s making Edgerton stand out today – and causing heads to pivot in the restaurant – is his hair, or lack thereof. It’s sheared so close to his skull he may as well have gone that last millimetre and embraced total baldness. And, in fact, that’s his very next step because when we meet, the 40-year-old actor is on the verge of heading to Spain to play the pharaoh Ramses in Ridley Scott’s hefty-budgeted epic Exodus: Gods and Kings.

More on Exodus later, but the film we’re meeting to discuss is Felony, a gritty Aussie thriller about a Sydney detective who knocks a newspaper boy off his bike while driving home from a night of boozy celebration with his drugs-squad colleagues. The accident leaves the boy in a coma, but Edgerton’s Malcolm, despite summoning an ambulance, subsequently lies about his involvement, instigating a downward spiral of events. Besides starring in Felony, Edgerton wrote the screenplay and produced this dark morality tale. Neither are first-time responsibilities for him: he has written and produced shorts and the feature-length crime thriller The Square (2008) with his older brother Nash, who typically directs their collaborations, and he also has a story credit on The Rover, the Guy Pearce-Robert Pattinson drama that was released over the summer.

Tom Hardy (left) plays the son of an alcoholic former boxer played by Joel Edgerton (right) in 2011 film 'Warrior' (AP)

Felony is about an ordinary man who makes a terrible decision. A well-constructed psychological exploration, the film also stars Jai Courtney as a rookie with a growing suspicion of Malcolm, Tom Wilkinson as a grizzled vet closing ranks to protect his fellow cop and Melissa George as Malcolm’s wife, willing to keep silent to protect her family. “I wrote the first draft just based on all the cops shows I’d ever seen,” says Edgerton. “I spewed it out and thought, ‘I’ll check the authenticity later’. Which is what I did.”

The actor knows a few Blacktown cops from his youth – although, he insists, not through his own run-ins with them (“I was a good boy; I was never in trouble for anything”) – and sought out their input as he progressed. Before the shoot, he invited Courtney to come hang out with them, going on drive-arounds and even getting slaughtered in a pub one night. “Everyone caught a cab home at the end of the night in case you’re wondering,” Edgerton laughs. “But they really helped us because we wanted to feel authentic but we also wanted them to be relatable. ”

Edgerton is still as matey as when I first encountered him for Warrior. Since the twin thrust of Animal Kingdom and Warrior launched him, he has gone on to appear in the The Thing remake, Zero Dark Thirty and The Great Gatsby, but he laughs when I mention “stardom”. Surely becoming best mates with Sean Penn – he brought Penn to Idris Elba’s 40th birthday bash – is incontrovertible evidence that life is very different now. “Aw, look,” Edgerton sighs, “I met Sean over a conversation we had about Haiti. He had seen Warrior and he paid me a lovely compliment and I ended up having dinner with him. He invited me to Haiti to look at the work he was doing there. But I feel weird talking about it. I could tell you about lots of other friends that are very special in my life I’ve known for a lot longer than Sean. He’s just a good guy who does good work.”

Edgerton recalls on his first trip to LA feeling in awe when he spotted Elizabeth Taylor dining with James Earl Jones, and being invited to a house-party that was wall-to-wall A-listers. “It was like a moving version of Madame Tussaud’s. I was like, ‘wait, stop them, they’re all moving!’.”

“My theory about actors,” he continues, “is that we’re all desperately insecure and we lacked love in our childhoods and so now we’ve got a job where we’re seeking the attention of a lot of people. But if someone said, ‘in that room over there are 500 of your most avid fans and they can’t wait to see you’, we’d be like…” Edgerton recoils like a vampire from daylight. “There’s an insecurity that’s so deep and that’s why I think all actors just bounce around bumping into each other. Because they get so hounded when they go out in public, they all cling to each other and hide in little rooms.”

The aforementioned Exodus will only raise his profile higher. Scott’s Biblical epic is the biggest role yet in Edgerton’s late-blooming career. If this straight-up blue-collar boy from Oz appears an unusual choice to portray the Old Testament’s plague-afflicted pharaoh – indeed, the director’s decision to have all white leads playing Egyptians is a controversial one – he seemed equally at odds for the part of aristocratic schmuck Tom Buchanan in Gatsby and ended up stealing Baz Luhrmann’s film. “All I can say is working with Ridley Scott is a dream come true,” he demurs. “He’s a great man and I feel very safe with him, which helps me because I get very nervous going into a movie like this.”

Edgerton’s other project is the spectacularly troubled siege Western Jane Got a Gun. Lynne Ramsay walked off set on the first day, leaving the Natalie Portman vehicle in shambles and actors dropping out with abandon, until Edgerton’s Warrior colleague O’Connor grabbed the reins. In the turmoil, Michael Fassbender, Jude Law and Bradley Cooper all came and went, Edgerton was switched (by Ramsay) from playing the villain to Jane’s ex-lover and Ewan McGregor finally stuck around as the former to allow the film to get made; credit to Edgerton, he still believes something good will emerge from the rubble. “All sorts of things were reported and some of it was true and some of it false,” he says. “But ultimately, audiences don’t know who liked each other, what bad things happened, whether a director and actor hated each other. In the end, a movie gets judged for what it is.”

Don’t ask Edgerton, one of the nicest and most polite actors around, to air that film’s dirty laundry any more than that. “I grew up being taught, ‘do unto others as they would do unto you,’” he says. “I would get scolded for not being polite. And look, I’ve got a great job, I’m in the prime of my life, I’ve a lot of gratitude for how things have panned out. I do my grumbling on my own.”

‘Felony’ is released on video-on-demand on 27 October; ‘Exodus: Gods and Kings’ is released in UK cinemas on 26 December